Site content related to keyword: "ArcGIS"

This vector data set contains the rock unit polygons for the surficial geology in the Delaware Coastal Plain covered by DGS Geologic Map Series No. 22 (Sharptown, Laurel, Hebron, and Delmar Quadrangles, Delaware). The geological history of the surficial geologic units in western Sussex County is that of deposition of the Beaverdam Formation and its subsequent modification by erosion and deposition related to the sea-level fluctuations during the Pleistocene. The geology reflects this complex history by the cut and fill geometry of the middle and late Pleistocene deposits into the Beaverdam Formation. The geology is further complicated by periglacial activity that produced dune deposits and Carolina Bays in the map area, which modified the land surface.

This vector data set contains the rock unit polygons for the surficial geology in the Delaware Coastal Plain covered by DGS Geologic Map Series No. 21 (Trap Pond and Pittsville Quadrangles, Delaware). The geological history of the surficial units of the Trap Pond and the Delaware portion of the Pittsville Quadrangle was the result of deposition of the Beaverdam Formation and its subsequent modification by erosion and deposition related to the sea-level fluctuations during the Pleistocene. The geology reflects this complex history by the cut and fill geometry of the Middle and late Pleistocene deposits into the Beaverdam Formation. The geology is further complicated by periglacial activity that produced dune deposits and Carolina Bays in the map area, which modified the land surface. Surficial geologic mapping was conducted using field maps at a scale of 1:12,000 with 2-foot contours. Stratigraphic boundaries drawn at topographic breaks reflect detailed mapping using contours not shown on this map.

This vector data set contains the rock unit polygons for the surficial geology in the Delaware Coastal Plain covered by DGS Geologic Map Series No. 20 (Millsboro and Whaleysville Quadrangles). The geological history of the surficial units of the Millsboro Quadrangle and Delaware portion of the Whaleysville Quadrangle was the result of deposition of the Beaverdam Formation during the late Pliocene and its subsequent modification by erosion and deposition related to sea-level fluctuations during the Pleistocene and late Pleistocene upland swamp and bog deposition. The geology at the land surface was then further modified by periglacial activity that produced dune deposits and Carolina Bays in the map area. Surficial geologic mapping was conducted using field maps at a scale of 1:12,000 with 2 foot contours. Stratigraphic boundaries drawn at topographic breaks reflect detailed mapping using contours not shown on this map. An additional dataset of datapoints used to generate rock unit polygons for the surficial geology in the Delaware Coastal Plain covered by DGS Geologic Map Series No. 20 (Millsboro and Whaleysville Quadrangles) exists for use in conjunction with this dataset.

This vector data set contains the rock unit polygons for the surficial geology in the Delaware Coastal Plain covered by DGS Geologic Map Series No. 19 (Frankford and Selbyville Quadrangles). The geological history of the surficial units of the Frankford and Delaware portion of the Selbyville Quadrangles is that of deposition of the Beaverdam Formation during the late Pliocene and its subsequent modification by erosion and deposition related to sea-level fluctuations during the Pleistocene. The geology at the land surface was then further modified by periglacial activity that produced dune deposits in the map area. Mapping was conducted using field maps at a scale of 1:12,000 with 2 foot contours. Stratigraphic boundaries drawn at topographic breaks reflect detailed mapping related to contours not shown on this map. An additional dataset of datapoints used to generate rock unit polygons for the surficial geology in the Delaware Coastal Plain covered by DGS Geologic Map Series No. 19 (Frankford and Selbyville Quadrangles) exists for use in conjunction with this dataset.

Three datasets are included: the official state boundary line, the county boundary lines, and the land/shore outline. These geospatial data files comprise the bounding lines relating to the political boundary delineation for the State of Delaware as well as the shoreline taken from the 2002 orthophotos of Delaware.

Elevation contours at 2 foot intervals for the State of Delaware were produced for New Castle and Kent Counties based on the 2007 LIDAR) and for Sussex County (based on the 2005 LIDAR.) Data are in line shapefile format.

This vector data set contains the rock unit polygons for the surficial geology in the Delaware Coastal Plain covered by DGS Geologic Map Series No. 18 (Bethany Beach and Assawoman Bay Quadrangles). The geologic history of the surficial units of the Bethany Beach and Assawoman Bay Quadrangles is that of deposition of the Beaverdam Formation and its subsequent modification by erosion and deposition related to sea-level fluctuations during the Pleistocene. The geology reflects this complex history onshore, in Indian River Bay and Assawoman Bay, and offshore in the Atlantic Ocean. Erosion during the late Pleistocene sea-level lowstand and ongoing deposition offshore and in Indian River Bay during the Holocene rise in sea level represents the latest of several cycles of erosion and deposition. An additional dataset of datapoints used to generate rock unit polygons for the surficial geology in the Delaware Coastal Plain covered by DGS Geologic Map Series No. 18 (Bethany Beach and Assawoman Bay quadrangles) exists for use in conjunction with this dataset.

This vector data set contains the rock unit polygons for the surficial geology in the Delaware Coastal Plain covered by DGS Geologic Map Series No. 17 (Harbeson quadrangle). The complex geologic history of the surficial units of the Harbeson Quadrangle is that of deposition of the Beaverdam Formation and its subsequent modification by erosion and deposition related to sea-level fluctuations during the Pleistocene. The geology is further complicated by periglacial activity that produced dune deposits and Carolina Bays scattered throughout the map area.

This vector data set contains the rock unit polygons for the surficial geology in the Delaware Coastal Plain covered by DGS Geologic Map No. 16 (Fairmount and Rehoboth Beach quadrangles). The geologic history of the surficial units of the Fairmount and Rehoboth Beach quadrangles is that of deposition of the Beaverdam Formation and its subsequent modification by erosion and deposition related to sea-level fluctuations during the Pleistocene. The geology reflects this complex history both onshore, in Rehoboth Bay, and offshore. Erosion during the late Pleistocene sea-level low stand and ongoing deposition offshore and in Rehoboth Bay during the Holocene rise in sea level represent the last of several cycles of erosion and deposition.

To facilitate the GIS community of Delaware and to release the geologic map of the Fairmount and Rehoboth Beach quadrangles with all cartographic elements (including geologic symbology, text, etc.) in a form usable in a GIS, we have released this digital coverage of DGS Geological Map 16. The update of earlier work and mapping of new units is important not only to geologists, but also to hydrologists who wish to understand the distribution of water resources, to engineers who need bedrock information during construction of roads and buildings, to government officials and agencies who are planning for residential and commercial growth, and to citizens who are curious about the bedrock under their homes. Formal names are assigned to all rock units according to the guidelines of the 1983 North American Stratigraphic Code (NACSN, 1983).

This vector data set contains the rock unit polygons for the surficial geology in the Delaware Coastal Plain covered by DGS Geologic Map No. 15 (Geologic Map of the Georgetown Quadrangle, Delaware). The geologic history of the surficial geologic units of the Georgetown Quadrangle is primarily that of deposition of the Beaverdam Formation and its subsequent modification by erosion and deposition of younger stratigraphic units. The age of the Beaverdam Formation is uncertain due to the lack of age-definitive fossils within the unit but is thought to be between late Pliocene to early Pleistocene in age. Refer to Ramsey, 2010 (DGS Report of Investigations No. 76) for details regarding the stratigraphic units.

To facilitate the GIS community of Delaware and to release the geologic map of the Georgetown Quadrangle with all cartographic elements (including geologic symbology, text, etc.) in a form usable in a GIS, we have released this digital coverage of DGS Geological Map 15. The update of earlier work and mapping of new units is important not only to geologists, but also to hydrologists who wish to understand the distribution of water resources, to engineers who need bedrock information during construction of roads and buildings, to government officials and agencies who are planning for residential and commercial growth, and to citizens who are curious about the bedrock under their homes. Formal names are assigned to all rock units according to the guidelines of the 1983 North American Stratigraphic Code (NACSN, 1983).

This digital product contains gridded estimates of water-table (wt) elevation and depth to water (dtw) under dry, normal, and wet conditions for New Castle County, Delaware excluding the Piedmont. Files containing the point data used to create the grids are also included. This work is the final component of a larger effort to provide estimates of water-table elevations and depths to water for the Coastal Plain portion of Delaware. Mapping was supported by the Delaware Department of Natural Resources and Environmental Control and the Delaware Geological Survey.

These grids were produced with the same multiple linear regression (MLR) method as Andres and Martin (2005). Briefly, this method consists of: identifying dry, normal, and wet periods from long-term observation well data (Db24-01, Hb14-01); estimating a minimum water table (Sepulveda, 2002) by fitting a localized polynomial surface to elevations of surface water features (e.g., streams, swamps, and marshes); and, computing a second variable in the regression from water levels observed in wells. Separate MLR equations were determined for dry, normal, and wet periods and these equations were used in ArcMap v.9 (ESRI, 2004) to estimate grids of water-table elevations and depths to water. New Castle County was divided into a northern section and a southern section with the C&D Canal being the natural line of demarcation. A minimum water-table surface was then calculated for both the northern and southern sections of New Castle County. However, dividing the county, as well as the water-level data, into two sections did not result in sufficient regression coefficients for use in the estimation process. Therefore, the data (minimum water-table surface and water-level data) were merged together and the water-table elevation and depth to water grids for dry, normal, and wet conditions were then calculated for the county as a whole.

This digital product contains gridded estimates of water-table (wt) elevation and depth to water (dtw) under dry, normal, and wet conditions for Kent County, Delaware. Files containing the point data used to create the grids are also included. This work is the final component of a larger effort to provide estimates of water-table elevations and depths to water for the Coastal Plain portion of Delaware. Mapping was supported by the Delaware Department of Natural Resources and Environmental Control and the Delaware Geological Survey.

These grids were produced with the same multiple linear regression (MLR) method as Andres and Martin (2005). Briefly, this method consists of: identifying dry, normal, and wet periods from long-term observation well data (Hb14-01, Jd42-03, Mc51-01, Md22-01); estimating a minimum water table (Sepulveda, 2002) by fitting a localized polynomial surface to elevations of surface water features (e.g., streams, swamps, and marshes); and, computing a second variable in the regression from water levels observed in wells. A separate MLR equation was determined for dry, normal, and wet periods and these equations were used in ArcMap v.9 (ESRI, 2004) to estimate grids of water-table elevations and depths to water. Kent County was divided into three regions (south, central, north). A minimum water-table surface was calculated for each of these areas and were merged together to create a single minimum water-table surface for the entire county. This grid was filtered and smoothed to eliminate edge effects that occurred at the boundaries between each of the three regions. Water-table elevation and depth to water grids for dry, normal, and wet conditions were then calculated for the county as a whole.

This digital product contains gridded estimates of water-table (wt) elevation and depth to water (dtw) under dry, normal, and wet conditions for Sussex County, Delaware. Files containing the point data used to create the grids are also included. This work is the final component of a larger effort to provide estimates of water-table elevations and depths to water for the Coastal Plain portion of Delaware. Mapping was supported by the Delaware Department of Natural Resources and Environmental Control and the Delaware Geological Survey.

These grids were produced with the same multiple linear regression (MLR) method as Andres and Martin (2005). Briefly, this method consists of: identifying dry, normal, and wet periods from long-term observation well data (Nc45-01, Ng11-01, Qe44-01); estimating a minimum water table (Sepulveda, 2002) by fitting a localized polynomial surface to elevations of surface water features (e.g., streams, swamps, and marshes); and computing a second variable in the regression from water levels observed in wells. A separate MLR equation was determined for dry, normal, and wet periods, and these equations were used in ArcMap v.9 (ESRI, 2004) to estimate grids of water-table elevations and depths to water. Grids produced in this project were merged with those previously completed for eastern Sussex and smoothed to minimize edge effects.

The unconfined portion of the Columbia aquifer is a key hydrologic unit in Delaware, supplying water to many agricultural, domestic, industrial, public, and irrigation wells. The aquifer is recharged through infiltration of precipitation and is the source of fair-weather stream flow and water in deeper confined aquifers. The aquifer occurs in permeable sediments ranging in age from Miocene to Recent. Over most of Delaware, the top of the unconfined or water-table portion of the Columbia aquifer occurs at depths less than 10 feet below land surface. Because of the permeable character of the aquifer and its near-surface location, the unconfined aquifer is highly susceptible to contamination.

The scanned raster and vector datasets contains the rock unit polygons for the surficial geology for DGS Geologic Map No. 8 (Milford-Mispillion River Quadrangles). This map is the first detailed surficial geologic map in southern Kent and northern Sussex counties.

The vector and raster data sets contains the rock unit polygons for the surficial geology for DGS Geologic Map No. 10. This map is of the crystalline bedrock units in the Piedmont of Delaware and adjacent Pennsylvania.

This data set contains the rock unit polygons for the surficial geology in ESRI shapefile format for DGS Geologic Map No. 14 (Geologic Map of Kent County, Delaware). This map shows the surficial geology of Kent County, Delaware, at a scale of 1:100,000.